Microsoft are scared becuase many people will realise that a Chromebook is all they need to browse the web, talk to their freinds, do their facebook/twitter, tweak a few uploaded photos from their android phone, edit a document with sufficient features (bold, centre, underline, font, image, table...), video conference, ... and more...

... without the need for an expensive overly complex operating system with buckets and buckets of years worth of unnecessary software.